Process of using a plug flow hydrolysis reactor having a slurry introduction device

Abstract

Provided herein is a process for hydrolyzing a cellulosic feedstock to produce sugar. The process comprises introducing a pretreated cellulosic slurry to an inlet region of a plug flow hydrolysis reactor using a slurry introduction device that reduces the axial momentum of the slurry at the surface of the reactor contents. The cellulosic feedstock slurry is hydrolyzed in the plug flow hydrolysis reactor by contacting the cellulosic feedstock with at least cellulase enzymes to produce glucose. Also provided herein is a vertically-oriented, unmixed downflow hydrolysis reactor for hydrolyzing a pretreated cellulosic feedstock slurry which comprises such a slurry introduction device disposed in a top region thereof.

We claim: 
     
       1. A process for producing glucose from a cellulosic feedstock, said process comprising the steps of:
 (i) providing a pretreated cellulosic feedstock slurry having an undissolved solids content of between about 5 and about 40 wt % undissolved solids; 
 (ii) conveying the pretreated cellulosic feedstock slurry to a continuous plug flow hydrolysis reactor; 
 (iii) introducing the cellulosic feedstock slurry to an inlet region of the continuous plug flow hydrolysis reactor using a slurry introduction device that reduces axial momentum of the slurry at the surface of the reactor contents; and 
 (iv) hydrolyzing said pretreated cellulosic feedstock slurry in the plug flow hydrolysis reactor by contacting the cellulosic feedstock with at least cellulase enzymes to produce glucose. 
 
     
     
       2. A process for producing glucose from a cellulosic feedstock, said process comprising the steps of:
 (i) providing a pretreated cellulosic feedstock slurry having an undissolved solids content of between about 5 and about 40 wt % undissolved solids; 
 (ii) conveying the pretreated cellulosic feedstock slurry to a continuous plug flow hydrolysis reactor; 
 (iii) introducing the cellulosic feedstock slurry to an inlet region of the continuous plug flow hydrolysis reactor using a slurry introduction device that reduces axial momentum of the slurry at the surface of the reactor contents; and 
 (iv) hydrolyzing said pretreated cellulosic feedstock slurry in the plug flow hydrolysis reactor by contacting the cellulosic feedstock with at least cellulase enzymes to produce glucose, 
 wherein the slurry introduction device comprises two or more feed ports that introduce slurry horizontally through a wall of said reactor adjacent to a top region of the reactor contents. 
 
     
     
       3. The process of  claim 1 , wherein the hydrolysis is carried out with beta-glucosidase. 
     
     
       4. The process of  claim 1 , wherein a partially hydrolyzed cellulosic feedstock from step (iv) is fed to a mixed hydrolysis reactor and further hydrolyzed therein. 
     
     
       5. The process of  claim 1 , wherein the portion of the cellulose hydrolyzed in the plug flow reactor is between about 10 wt % and about 100 wt %. 
     
     
       6. The process of  claim 1 , wherein the slurry introduction device further comprises:
 a) two or more feed ports that introduce slurry horizontally through a wall of said continuous plug flow hydrolysis reactor adjacent to a top region of the reactor contents; 
 b) a feed port that terminates with a distributor plate disposed in an inlet region of the continuous plug flow hydrolysis reactor; 
 c) a pipe and first and second disk-shaped distributor plates, said first and second disk-shaped distributor plates positioned one on top of the other with a gap therebetween such that pretreated cellulosic feedstock slurry fed through the pipe flows through the gap; or 
 d) a pipe and a rotatable horizontal arm, said rotatable arm comprising first and second outlet ports. 
 
     
     
       7. The process of  claim 1 , wherein the slurry introduction device further comprises a distributor plate disposed in an inlet region of the continuous plug flow hydrolysis reactor. 
     
     
       8. The process of  claim 1 , wherein the slurry introduction device further comprises a pipe and first and second disk-shaped distributor plates, said first and second disk-shaped distributor plates positioned one on top of the other with a gap therebetween such that pretreated cellulosic feedstock slurry fed through the pipe flows through the gap. 
     
     
       9. The process of  claim 1 , wherein the slurry introduction device further comprises a pipe and a rotatable horizontal arm, said rotatable arm comprising first and second outlet ports. 
     
     
       10. The process of  claim 1 , wherein the slurry introduction device further comprises a dissipator device configured to disperse the slurry at an angle off-set from the direction of slurry flow. 
     
     
       11. The process of  claim 1 , wherein the slurry introduction device further comprises a distributor plate. 
     
     
       12. The process of  claim 1 , wherein the slurry introduction device further comprises an inverted cone. 
     
     
       13. The process of  claim 1 , wherein the slurry introduction device further comprises:
 a) one or more feed ports that introduce slurry horizontally through a wall of said continuous plug flow hydrolysis reactor adjacent to a top region of the reactor contents; 
 b) a feed port that terminates with a distributor plate disposed in an inlet region of the continuous plug flow hydrolysis reactor; 
 c) a pipe and first and second disk-shaped distributor plates, said first and second disk-shaped distributor plates positioned one on top of the other with a gap therebetween such that pretreated cellulosic feedstock slurry fed through the pipe flows through the gap; 
 d) a pipe and a rotatable horizontal arm, said rotatable arm comprising first and second outlet ports; or 
 e) an inverted cone.